Watering Lawns in Central Texas


Understanding the water needs of our lawns will ensure greater success with maintaining a healthy lawn.  A lawn that is properly watereed can compete aggressively with weeds and avoid stress that contributes to lawn diseases.

LAWNS: Creating a deep root system is probably the single-most important goal during hot weather.  Lawns should be watered to a depth of 6 inches during each irrigation.  To calculate the length of time to run irrgation, collect several empty tuna fish cans or cat food cans and set them randomly around the yard.  Run the irrigation for the length of time you are used to running it.  Check the amounts of water collected in the cans and calculate the average amount.  Next, dig down in the soil to see to what depth the water reached.  Now you can calculate any adjustment that might be needed in water time.  Let's say you collected an average of 1/2 inch of water in the cans in a 15 minute time period, and the water penetrated the soil to a depth of 3 inches.  You can now calculate that it would take approximately 30 minutes, or 1 inch of water to penetrate to a depth of 6 inches.  Sloped yards may need this amount applied in two time periods, an hour or so apart, in order to slow down run-off on the slope.  Soil depth and type plays a role in water perolation rate.

Determining frequency of watering is the next step in maintaining a healthy lawn.  It is important to water thoroughly, as described above, and not water again until the lawn is approaching the stress point.  This stress point is seen in St. Augustine grass as the leaves "folding", and in Bermuda and Zoysia grasses as when a footprint does not "bounce" back.  This is the point at which irrigation should be timed.  Spending a week or two observing your lawn and setting your irrigation accordingly will ensure a more drought-tolerant lawn.  Your lawn will be better able to withstand the stress of water rationing, and your water bills will reflect this "water-wise" approach to irrigation.  During a "drought year", water periodically during the winter; grass roots are still alive and require moisture.

Remember to raise the mower height in the heat of the summer.  The leaves will shade the soil and conserve moisture.  Try not to remove more than 1/3 of the leaf blade each mowing.  Water in the morning (daylight) so leaves will dry quickly and be less prone to disease.  This is especially important in the spring and fall when temperatures are cool and brown patch fungus is prevalant.

Last, but not least, try to observe your irrigation system while it is running - the reason for that brown grass may become obvious!